PURPOSE: To dissolve the sample in the solvent quickly and at the same time wash off and dissolve the solid sample which happens to adhere to the inside wall of container by vibrating and moving round the funnel-type container at an adequate cycle.

CONSTITUTION: A fixed quantity of sample and solvent is put in the cylindrical container 11, which revolves circularly with the revolution of motor 2. By adjusting the revolving speed of a motor 2, the cycle of circular movement can be varied, and when the solvent resonates or almost resonates with the circular movement of the container 11, the solvent is likely to rise up along the inside wall face of container 11. The helical spring 10, an elastic material, prevents the container 11 from revolving around the motor shaft 3. When solution is completed, the revolution of motor 11 stops, and the solution is sucked downward by the electric aspirator 15, a sucking means, to catch the insoluble foreign matters in the solution up on the filter 13.